– Doggy Pounds,
I’m going into your wow, that’s super washed out.
Whatever. This is your lab handout. If you take a look
at the lab handout I’ve divided the axial
musculature by function. I’ve sorted the 23
required muscles into categories based
on function. So my first category
that I have are muscles of facial expression. And this, actually,
I don’t think I put it that way, I just said muscles of the face. But their function is facial
expression. So, let’s look at the muscles that we need to know
for facial expression. For all of them you do not
have to memorize the attachments of these muscles
of facial expression. You do need to know their action and you need to be able
to find them. I would argue that if you
know their action and you know where to find them
you could give a rocking solid argument
or educated guess about the attachments
of these muscles. But it’s not something I’m
actually going to ask you on a test or a quiz. So if we were to take a look at
who are we going to name here, let’s name, oh sure,
we’ll go blue, frontalis muscle. We have to know this one.
From– and the occipitofrontalis is its
full name, the frontal belly as opposed
to it has an occipital belly, which is in the posterior
portion of your head. We’re just,
frontalis muscle is fine. If you want to call it
occipitofrontalis with the frontal belly,
I’m fine with that too. Excuse me. Okay, frontalis muscle,
look at the fiber direction. You can see it’s totally
attached to like your skull. What is it going to do? It raises your eyebrows. That’s the frontalis
muscle right here, it makes these lovely little
wrinkles here that oh my gosh, how funny is it that people
don’t want those wrinkles there when they raise their eyebrows, and so they put in Botox
to make it I guess so they can never raise
their eyebrows again, if this,
if occipitofrontalis muscle was actually paralyzed
by Botox toxin. Holy Crud, humans are so weird. Okay, orbicularis oculi,
look at this one. Orbicularis oculi surrounds
like an orb, a circle– a circular muscle
around the eye. Guess what orbicularis oris
is going to do if those muscle fibers shorten? Now think about this,
here’s the muscle, imagine all your thick and thin
filaments overlapping each other and the fibers shorten,
what happens around here? Like a like a that.
They cause your eyes to blink. Squinting is orbicularis oculi? Did I say oris
because I kind of think I did. Oculi, oculars,
I’m throwing things, that they go around your eyes. Orbicularis oris,
another round muscle, but this time it’s
surrounding your oral cavity. Orbicularis oris is
your kissing muscle. The action for orbicularis oculi
is definitely to kiss someone. So if you practice your muscles you can practice them
by kissing people and say, “I’m contracting
my orbicularis oris and now I’m contracting my
orbicularis oculi too”. Perfect. Buccinator, buccinator is
I would almost argue that buccinator is not
a muscle of facial expression, unless it’s more like a muscle that keeps food
from sticking in your cheeks, like it helps you keep food
in your mouth to chew. Here’s what the buccinator does, it’s a deep muscle
and it’s in your cheek itself. You can see it right here. We will be able
to see it on George the Man, and here’s what it does. Are you ready?
Not the first part. Not that part. I’m going to blow up my cheeks
and then I’m going to show– and then I’m going
to contract my buccinator. When I go like this, that means I’m about to
contract my buccinator. Ready?
Did you see that? Buccinator squishes your cheeks. And look at it,
look at those muscles. If that buccinator is
all stretched out when I blow air into my cheeks, and that the fibers
shorten like this, and then that shortening is
what squishes your cheeks in and blows the air out. Buccinator is called the,
like the trumpet player’s muscle because you
have to have a really rock star buccinator
to play the trumpet. Not that I’ve ever played
the trumpet before. One more, two more. Zygomaticus.
What? Zygomaticus is not listed. Zygomaticus.
I love the zygomaticus. Do you know why?
Look at this muscle. Look at where it attaches.
It’s actually two of them here. The attachment is right here. What is going to happen
is zygomaticus, it attaches to your cheekbone,
which is your zygomatic bone, and it attaches to the corners
of your lips. And when it contracts,
aww, it’s the smiling muscle. This is really awesome because
you have smiling and kissing that you have to practice to
practice your anatomy this week. I guarantee that I’m never going
to want to watch this lecture. Okay, zygomaticus makes
you smile. One more.
Platysma. Platysma isn’t on here. Platysma is the most
superficial muscle. It attaches to your chin.
It’s a weird one. It comes all the way
down through your neck and even attaches
like to this skin in here and guess
what it makes you do? Did you see I just
contracted my platysma? Yeah, that’s all platysma. So go ahead and do that.
Do that like, we call that a grimace face. Yeah, and that’s all platysma.
It’s an awkward muscle because it is so
unbelievably superficial. But in dissection
if you are not really careful about just getting
the thin layer of skin off, you will take platysma with you. That’s a sad story.
That’s it. Platysma is weird because it’s
a facial expression muscle, but it’s kind of found
in the neck, but I put it
in with facial expressions because it attaches here
to your face. And this is definitely
a facial expression. Okay, don’t put–
make that face anymore. Use your zygomaticus instead
and give me a great big smile and let’s do muscles
of our neck, if I can find out
how to turn this off, which is really important,
I have learned.